1. Field of the Invention
The present invention relates to trailers and more particularly to trailers and similar vehicles for hauling coils of steel and the like.
2. Discussion of the prior art
There has existed a need in the highway transportation of heavy coils of steel and other objects having a circular contour for the provision of a trailer bed construction which will firmly seat such coils and curb their tendency to roll. Most prior constructions which have attempted to solve this problem have provided superstructure on the trailer bed as upwardly extending rails, clamps and the like.
In the conventional method of transporting steel coils on highways and streets from the steel mills to steel fabricators, the coils are placed on a trailer bed in end-to-end position and held on the trailer by placing wood timbers along each side of the coils on the trailer floor and securing the coils in position with a number of large chains extending through the ID of the coils and fastened at their ends to side rails or the trailer frame. This method of securing the coils onto the trailer is not only laborious and time consuming, but also requires frequent replacement of the timbers from one load to another and is not a consistently reliable means of retaining the coils on the trailer because this method relies strictlyon the chains to secure the coils. Other methods, including the use of trailers having a longitudinal channel in the center of the bed have been tried but this latter type has had the inherent disadvantage that the trailer either will not safely haul different sized coils, or the coils are damaged by the supporting structure on which the coils are placed. The use of timbers in the channel type trailer to protect the coils has likewise required frequent replacement of the timbers involving substantial costs both of labor and material.
Coils of strip steel or other metal, generally range in weight from approximately 2,000 pounds to 67,000 pounds. It is obvious that if these coils are not firmly seated in position during transportation, great damage could result. It is necessary to provide against the tendency of the coils to roll and also to provide against the possible unbalancing of the coils along their transverse axes. Should the trailer become disconnected from the tractor, while traveling on the highway, it is extremely dangerous to have the load of coils accidentally fall from the trailer.
Several prior art attempts to provide trailer beds particularly adapted for hauling coils of steel which firmly seats such coils and prevents accidental displacement thereof.
U.S. Pat. No. 2,622,918 to Staffe discloses a trailer bed having a central longitudinally extending recess providing a trough for seating a heavy steel coil. The trough used by Staffe provides a six inch drop from the level of the trailer bed at the center of the trough and is twenty-seven inches in width.
U.S. Pat. No. 2,810,602 to Abrams discloses a vehicle body having longitudinally spaced load supports or stands. Each of the deck spaces in combination with the side walls of the stands form a trough for carrying the rolls of material with their axes disposed transversely of the vehicle. The troughs are of the same general shape except those over the wheels.
U.S. Pat. No. 2,971,795 to Winski, discloses a coil hauling vehicle provided with a longitudinal channel in the center of the trailer body. The coils are placed end to end in the channel with the sides of the coils resting on the convex surfaces on the support members. The frame structure consists of longitudinal I-beams extending the full length of the trailer body and has a wide portion above the wheels, a narrow portion above the tractor, and a connecting tapered portion.
U.S. Pat. No. 3,376,062 to Chosy et al discloses a trailer body provided with a well or channel in which a coiled product can be seated. The channel can be covered by cover members to carry a flat load.
U.S. Pat. No. 3,581,674 to O'Leary discloses a flat railway car in which a depressed center section of the car extends the length of the car to form a pocket or well to receive steel coils.
U.S. Pat. No. 4,451,188 to Smith discloses a rail car for carrying coiled material which can be converted from a first position to a second position to provide different trough arrangements for seating coils of different sizes.
None of the prior art trailers provide the necessary protection required for sudden stops or turns which are necessitated in emergencies on the highways which cause the prior art devices to become dangerous instrumentalities of death on the currently crowded highways. Each of the prior art trailers cradle the coil load substantially above the center of gravity and are merely adaptations of state-of-the-art trailers.